Vapor generator



M. FRISCH VAPOR GENERATOR Aug. 15, 1950 3 Sheets-Sheet 1 Filed NOV. 13, 1945 INVENTOR HART/N fP/JcH ATTORNEY Aug. 15, 1950 Filed Nov. 13, 1945 M. FRISCH 2,518,459

VAPOR GENERATOR 3 Sheets-Sheet 3 Patented Aug. 15, 1950 VAPOR GENERATOR Martin Frisch, New York, N. Y., asaignor to Foster Wheeler Corporation, New York, N. Y., a corporation of New York Application November 13, 1945, Serial No. 628,115

This invention relates to vapor generators.

The present invention provides a vapor generator in which the parts thereof are so constructed and arranged that a minimum amount of heating surface is required for a given vapor generating capacity. This invention also provides a vapor generator in which the combustion air is delivered thereto at higher than normal density and pressure. The present invention further provides a vapor generator in which the combustion air is delivered thereto at higher than normal density and pressure by a compressor which compressor is driven by a gas turbine actuated by combustion products from the generator.

The features and advantages which characterize the invention will be apparent from the following description when considered in connection with the accompanying drawings forming a pa thereof and in which:

Fig. 1 is a transverse sectional view of the vapor generator of the present invention taken on the line l--| of Fig. 2;

Fig, 2, is a sectional view taken on the line 22 of Fig. 1; Fig. 3 is a view similar to Fig. 2 but is taken on the line 3--3 of Fig. 1;

Fig. 4 is a longitudinal sectional view taken onthe line 6-4 of Fig. 2; and I Fig. is a diagrammatic view disclosing the arrangement of the various parts of the apparatus of the present invention.

Like characters of reference refer to the same parts throughout the views.

a plurality of sections, as shown, which sections are secured to vertically extending angle bars I. The angle bars I! and the casing 12 are supported at the bottom thereof on an annular girder l5.

Setting l0 has a dome-shaped metal top It with a flange l1 adapted to abut a flange I8 at the top :OfzjbhE casing, the flanges being secured together bybolts l9.

.IA substantiall vertical drum 20 is disposed centrally of the space formed by the cylindrically- I shaped wall II which drum comprises an upper chamber 2| and a lower chamber 22 spaced from one another and in communication through a downcomer section 23 of a lesser diameter than the jchambers2l Land. 22. The chamber 2| has a manhole openin 2! at the top thereof which is elosed by a cover12l while the chamber 22 has 2Q Claims. (Cl. 122-323) a manhole opening 22' at the bottom thereof closed by a cover 22". The downcomer section 23 extends along the longitudinal axis of the drum and is insulated by a covering of refractory 24. A plurality of concentric circular rows of vapor generating tubes 25 are disposed between the lower end of the chamber 2! and the upper end of the chamber 22, the tubes being in communication at the opposite ends thereof with said chambers respectively. As shown, tubes 25 are slightly bowed sothat they may be withdrawn through the opening 2|. Tubes 25 are inclosed in a passage 26 by a cylindrical outer wall 2i which has a flange 28 at the top thereof secured chamber 2 l.

to an annular angle bar 29. The angle bar 29 is, in turn, secured to the drum 20 adjacent the The passage is is divided into two passes 38 and 3! by diametrically opposed substantially vertical baiiles 32 and 33 positioned in passage 26. The bafiles 32 and 83 extend to a point short of the top of the passage 25 to provide an opening so that passes 36 and 3!! will be in communication with one another. The setting has a substantially circular floor above the chamber 22 comprising a metallic plate 34 having a covering of refractory 35 thereover and a circular roof comprising an annular metallic plate 36.

The metallic plate 36 is spaced from the domeshaped top it to form a chamber it into which air under pressure is introduced through an air inlet connection 84, as will hereinafter be fully described. Plate 36 is secured at the inner periphery thereof to the angle bar 28 and at the outer periphery thereof to a circular header 31 around the setting at the top of the wall II. A plurality of water wall tubes 38 project from the header 3'! across the roof of the setting along the cylindrical wall 21 of the passage 28 thence across the refractory floor 35 to a circular header 38 around the setting below the refractory wall II. The tubes 38 are closely spaced along the wall 21 but are spaced apart a greater distance at the point of connection thereof to the headers 31 and 39. Refractory is placed between the roof plate 38 and the portion of the tubes 38 projecting across the motor the setting. Header 31 is in communicaion with the chamber 2| of the drum 20 through a plurality of tubes 4| while the header 38 is in communication with the chamber 22 or said drum through tubes 42. The space between the outer wall 21 of the passage '26 and the outer peripheral wall ll of the setting is divided into a separately fired vapor generating section 43 and a separately fired superheater sectionJl by diametrically opposed header 52.

water wall screens '5 and 55 which extend radially adjacent the baflies 32 and 33 across the space between the walls 21 and H. The screen as comprises a row of spaced substantially vertical tubes 41 connected to a lower header 5t and an upper header 49 while the screen 55 comprises a row of spaced tubes 50 which extend substantially vertically between a lowerheader 5i and an upper The upper headers are in communication with the upper chamber 2l of the drum 26 while the lower headers of the sections are in communication with the lower chamber 22 of said drum. A semi-circular vapor generating furnace chamber 52 is thereby formed to theleft of the screens 55 and 65 while a semi-circular shaped superheater furnace chamber is formed to the right of the screens 55 and 66 as shown in Figs. 1 and 2. Vapor generating furnace chamber 52 has a plurality of tangent water wall tubes 55 along the outer periphery of said chamber adjacent thewall i l, the tubes 55 being connected at their upper ends to the circular header 31 and at the lower ends to the circular header 39. A substantially vertical superheater inlet header 55 extends along the outer periphery of the casing l2 adjacent the screen 55 while a superheater outlet header 55 extends vertically along the outer side of said casing adjacent the screen 56. A row of substantially horizontal superheater tubes 51 are in communication at one end thereof with the header 55 and at the opposite end with the header 56. Each of the tubes 51 has a portion 58 which projects inwardly from the header 55 to a point adjacent the water wall tubes 38 and another portion 55 which projects outwardly from the tubes 38 to the inner periphery of the refractory wall Ii; From the portion 59, the tubes 51 are bent to form a radiant section 60 along the inner periphery of the refractory wall H to a point adjacent the header 56 at which point the tubes project inwardly to a point adjacent the tubes 38 to form a section 6! and are thereafter bent to form a section 62 which projects outwardly from a point adjacent the tubes 38 to the header56. In this manner, convection superheating sections comprising the portions 58 and 59 and sections 6! and G2 are formed while a radiant superheating section comprising the portion 60 of the tubes 51 i formed along the wall I l. -The section 60 of the tubes 51 are tangent while the portions of the tubes 51 forming the convection superheating sections are spaced apart sufiiciently o permit the flow of gases therebetween.

Superheater tubes. '51 are divided into a plurality of passes so that vapor to be superheated will flow in series through the various passes from Y the upper part of the furnace chamber where the saturated vapor enters the header through the connection 82 to the superheated steam outlet 56' at the lowermost part of the header 56. As shown, the inlet header 55 'is divided into a plurality of separate chambers 92 by partitions 93 while the outlet header 56 is divided into a plurality of compartments 95 by partitions 95. The

tubes 51 serially connect a chamber 92 with a lower compartment 34 and the lower compart ment 96 with the next succeeding lower chamber 92 for as many passes as may be required to give the vapor being superheated the necessary velocity through the tubes '51 to produce the inside heat transfer rate required to prevent overheating of the tubes.

The superheater furnace chamber 55 is separately downwardly fired by a burner 63 while the vapor generating furnace chamber is separately fired in a similar manner by a burner 66. The wall 21 extends to a point short of the floor 35 at the left of sections 85 and 46 to thereby form a furnace gas outlet opening 65 from the vapor generating furnace chamber 52. The refractory floor 35 extends inwardly in the vapor generating section to the refractory insulation 25 while in the vapor superheating section the refractory floor extends'inwardly to the wall 21 to form a gas outlet opening 66 from the passage 6!. Refractory 61 is positioned along the portion of the drum 2i bordering the passage 66. The passage 66, as shown, is in communication with a passage gas outlet 68 which is connected to a gas turbine, as hereinafter set forth.

A vapor and liquid separator 69 is disposed in the chamber II of the drum 2t. Separator 69 comprises a cylindrically shaped shell 16 of a lesser diameter than the chamber 2! said shell forming acentrifugal chamber H. The cylindrically shaped shell 10 has a frustro-conical shapedbottom' 12 which abuts the upper end of the downc0mer-23 and is adapted to discharge thereinto through an outlet 13. The shell 10 at the top thereof has an annular member 1% of lesser diameter than the shell 10 projecting downwardly thereinto from a point short of the upper end of the chamber M. A top plate 15 i positioned across the upper end of the member 15 and is secured at the periphery thereof to the inner wall of the chamber H. The top plate 15 has an outlet opening 16 in communication with a vapor outlet chamber 16 at the top of the chamber 2!, the chamber 16 being separated from the chamber 2| by the top plate 15. A plurality of blades 11 extend substantially diagonally across the space 18 between the outer periphery of the member 14 and the inner periphery of the shell 10. The blades 11 are curved downwardly to impart a whirling motion to vapor flowing through the passages therebetween, as will hereinafter be fully set forth. A conical shaped member 19 is disposed adjacent the bottom of the shell 10 in spaced relationship with the outlet 13.

The chamber 16 is in communication with a vapor outlet ring through a plurality of tubes 8 I. The ring 80 is in communication with a vapor outlet pipe 82 which outlet pipe communicates with the superheater header 55.

As shown in Fig. 5, air under pressure and of a high density is supplied to the vapor generator through conduit 83 which is in communication at one end with the vapor generator through the connection 84 and at the opposite end is connected to an air compressor 85. The air compressor 85 is driven by a gas turbine 86 which turbine is actuated, as shown, by Bases of combustion from the vapor generator. The gases of combustion flow from the vapor, generator through the gas outlet 68 into the conduit 81 thence to the turbine 86. Exhaust gas from the turbine flows through the conduit 88 through an economizer 89 to a stack 90. In starting up the vapor generator of the present invention, it may be necessary, in order to secure air of the proper I let passage 85.

density and pressure. todrlve the compressor 33 by a turbine or electric motor 3|.

In operation, the vapor generator of the present invention is started by lighting the burner 34 which causes a stream of gases of combusl tion to flow downwardly in the chamber 52 and outwardly of said chamber through the gas outlet 3! thence upwardly over the vapor generating tubes 25 in the pass 33 of the passage 23. Air at the proper density and pressure is provided by the compressor 35 which is driven during the starting-up period by the turbine or motor 9i, said air entering the vapor generator through the conduit 33 and connection 33. The gases flow from the pass 30 over the top of the babies 32 and 33, downwardly over the vapor generating tubes 25 in the pass 3| and outwardly of the pass 3| through the outlet passage 33 thence outwardly of the setting through the passage gas outlet 68 to the gas turbine .83 through the conduit 81. Normally, the water level in the drum extends to the line WL in the chamber 2|. The circulation of water is downwardly through the downcomer 23 into the chamber 22 thence upwardly into the tubes and upwardly into the water wall tubes 54 and tubes 33 through the tubes 32 and header 33. Vapor generated in the tubes 54 and 38 flows into the upper header 3! thence through the tubes ii into the chamber 2| of the drum 20 while vapor generated in the tubes 25 flows upwardly into the chamber 2|. Vapor from the chamber 20 flows therefrom through the passages between blades 11. The blades Tl impart a circular movement to the vapor as it enters the shell W. Circular movement within the shell it separates liquid from vapor by centrifugal force, the liquid flowing downwardly through the bottom section 12 of the shell and into the downcomer23 while the separated vapor flows upwardly through the outlet opening in the top 175 into the chamber 76 thence through the pipes 8i into the ring 83 whence it flows into the outlet pipe 82 thence into the superheater inlet header 55. Vapor passes into the uppermost chamber 92 in header 55 through the pass 96 into the uppermost compartment 95 inthe header 58 thence serially through the next lower succeeding passes to the superheater vapor outlet 56'. In flowing through the various passes of the tubes 51, the vapor passes from a chamber 92 in header 55 through the convection section comprising the portions 58 and 59 and thence into the radiant sectioncomprising the portion then into the second convection section comprising the sections 6| and 52 of the tubes 51. From the second convection section, vapor flows into a compartment 94 of the superheater header 56. When sufiicient saturated steam is flowing into superheater tubes 51, the burner 63 is lighted which causes gases of combustion to flow downwardly therefrom into the superheater furnace chamber 53. Gases of combustion flow from the superheater chamber 53 in radiant heat exchange relationship with the section III of the superheater tubes 51 thence in convection heat exchange relationship with the portions 58, 59, I and 62 of the tubes 51, thereafter passing through the screens and .46 into the vapor generating furnace chamber 52 wherein the gases mix with the gases of combustion flowing downwardly from the burner 64. The mixed gases flow outwardly of the chamber 52 through the furnace gas out- With this arrangement, itwill be perceived that a compact vapor generator is provided. A compact vapor generating and superheating unit is also provided in which the vapor temperature is controlled by differential firing of the vapor generating furnace 52 and the vapor superheating furnace 53 and in which saturated vapor only may be obtained by firing the vapor generating furnace only. Since the vapor generator is operated under pressure, the size of the combustion chamber and the amount of heating surface required for a given capacity of vapor generation is reduced because the density of the air and combustion gases is increased. Due to the arrangement of the parts of the vapor generator of the present invention, the speed of travel of the gases therethrough is several times as great as in the usual pressure boiler so that a very high transfer rate and corresponding reduction in the required heating surface is obtained.

Although a preferred form of the invention has been disclosed, the principles of the invention may be embodied in other forms. For example, instead of the drum 20, an upper drum and a lower drum connected by a plurality of downcomer tubes, instead of the downcomer section 23, may be used. Each of the furnaces 52 and 53 may be fired by one or more burners if desired.

Changes may be made in the form, location and arrangement of the several elements of the generator disclosed without departing from the principles of the invention. Accordingly, the invention is not to be limited excepting by the scope of the appended claims.

What is claimed is:

. 1. A vapor generator comprising a setting, an upper vapor and liquid container, a lower liquid container below the upper container, a bank of vapor generating tubes extending between the containers, downcomer means disposed within the bank of tubes, heat insulating means separating thedown-comer from said tube bank, a furnace surrounding the bank of tubes, a superheater and also vapor generating tubes in one portion of the furnace, vapor generating tubes in another portion of the furnace, separate burners for firing each of said furnace portions, and

partition means forming a, passage around the tube bank and separating said bank from the furnace, the furnace having a gas outlet opening in communication with the passage and positioned to receive gases of combustion from said one furnace portion after the gases have passed in heat exchange relationship with the superheater and the vapor generating tubes and to receive the gases from said other furnace portion after the gases have passed in heat exchange relationship with the vapor generating tubes, the passage having a gas outlet through which gases flow from the passage, the furnace outlet opening and the gas outlet being so disposed in relationship to each other that gases of combustion from the furnace flow in heat exchange. relationship with the tube bank in flowing through said passage from said outlet opening to the outlet.

2. A vapor generator comprising a setting, an upper vapor and liquid container, a lower liquid container substantially vertically below the uppercontainer, a bank ofsubstantially vertically extending vapor generating tubes between the containers, downcomer means disposed within the bank of tubes, heat insulating means separating the downcomer from the tube bank, a substantially annular shaped furnace'surrounding the bank of tubes, a superheater in one portion of the furnace, a burner for firing said one portion, a separate burner for firing another portion of the furnace, and partition means forming a passage around the tube bank and separating said bank from the furnace, the furnace having a gas outlet opening in communication with the said passage andpositioned to receive gases of combustion from said one furnace portion after the gases'have passed in heatexchange relationship with the superheater and to receive gases from said other portion of the furnace, the said passage having a gas outlet through which gases flow from the said passage, the furnace gas outlet opening and the said passage gas outlet being so disposed in relationship to each other and the tube bank that gasesof combustion from the furnace flow into said passage through said gas outlet opening and flow in heat exchange relationship with the tube bank in flowing through said passage from said outlet opening to said outlet.

3. A vapor generator comprising a setting, a substantially annular furnace in the setting, burners spaced from each other circumferentially of the furnace, a substantially vertically extending vapor and liquid drum disposed centrally of the furnace, said drum having an upper vapor and liquid chamber, a lower liquid chamber and an elongated connecting chamber extending along the vertical axis of the drum, the connecting chamber being of lesser diameter than the upper and lower chambers, a bank of vapor generating tubes adjacent the connecting chamber and connecting said upper and lower chambers, the width of the tube bank at the point of connection with saidchambers being less than the diameter of the chambers, heat insulating means separating the connecting chamber from the tube bank, partition means forming a passage bank, partition means forming a passage around the tube bank and separating the bank from the furnace, the furnace having a gas outlet opening in communication therewith and with said passage and through which gases of combustion produced by said burners flow into said passage, the passage having a gas outlet through which gases flow therefrom and from the setting, the outlet and the outlet opening being so disposed in relationship to. each other that gases of combustion from the furnace flow in heat exchange relationship with the tube bank in flowing through said passage from said furnace gas outlet opening to the passage gas outlet, and a superheater disposed in heat exchange relation-. ship with the gases flowing from at least one but not all of the burners to the gas outlet.

5. A vapor generator comprising a setting, a substantially annular furnace in the setting, a substantially vertically extending vapor and liquid drum disposed centrally of the furnace, said drum having an upper vapor and liquid chamber, a lower liquid chamber and an elongated connecting chamber extending along the vertical axis of the drum, the connecting chamber being of lesser diameter than the upper and lower chambers, a bank of vapor generating tubes adjacent the connecting chamber and connecting said upper and lower chambers, the width of the tube bank at the point of connection with said chambers being less than the diameter of the chambers,

heat insulating means separating the connecting chamber from the tube bank, rows of spaced around the tube bank and separating the bank from the furnace, the furnace having a gas outlet opening in communication therewith and with saidpassage and through which gases of combustion produced by said burners'flow into said pass he passag h ving a soutiet through which gases flow therefrom and from the set ting, the outlet and the eutlet'opening being so disposed in relationship to each other that gases of combustion from the furnace flow in heat ex:

change relationship with the tube bank in flowing through said passage from said furnace gas out:- let opening to the passage gas outlet, and a superheater disposed in heat exchange relationship with the gases flowing from at least one but not all of the burners to the gas outlet.

4. Vapor generating apparatus comprising a vapor generator having a setting, a substantially annular furnace in the setting, burners spaced from each other circumferentially of the furnace, means for introducing air under pressure to the furnace, a substantially vertically extending vapor and liquid drum disposed centrally of the furnace, said drum having an upper vapor and liquid chamber, alower liquid chamber and an elongated connecting chamber extending along the vertical axis of the drum, the connecting chamber being of lesser diameter than the upper and lower chambers, a bank of vapor gen- .erating'tubes adjacent the connecting chamber tubes extending transversely of the furnace and dividing it into a vapor generating furnace chamher and a superheater furnace chamber, burner means for firing the vapor generating furnace chamber, burner means for firing the superheater furnace chamber, and partition means forming a' passage around the tube bank and separating the bank from the furnace, the furnace having a gas outlet opening in communication with'the vapor generating furnace chamber and said passage and through which outlet gases of combustion from both of said burner means flow into said passage, the passage having a gas that gases of combustion from the furnace flow in heat exchange relationship with the tube bank 'in flowing through said passage from said furnace gas outlet opening to the passage gas outlet, and a superheater disposed in said superheater furnace chamber.

6. A vapor generator comprising a setting, a substantially annular furnace in the setting, a substantially vertically extending vapor and liquid drum disposed centrally of the furnace, said drum having an upper vapor and liquid chamber, a lower liquid chamber and an elongated connecting chamber extending along the vertical axis of the drum, the connecting chamber being of lesser diameter than the upper and lower chambers, a bank of vapor generating tubes a'djacent the connecting chamber and connecting said upper and lower chambers, the width of the nace chamber and a superheater furnace cham-,

ber, burner means for firing the vapor generat- 11 tion means forming a passage around the tube bank and separating said bank from the furnace,

the passage having a gas inlet opening adjacent one end thereof in communication therewith and with the furnace and a gas outlet opening through which gases flow from the passage, the inlet and outlet openings being so disposed in relationship substantially annular furnace in the setting,

forming curved passages in said opening for imparting a whirling movement to the vapor and liquid, the cylindrical member having a liquid,

outlet at the bottom thereof in communication with said connecting chamber and a vapor out let in communication with the means communicating with the annular ofitake pipe.

10. A vapor generator comprisinga setting, an upper vapor and liquid container, a, lower-liquid container below the upper container, a bank of vapor generating tubes extending between the containers-downcomer means disposed within the bank of tubes, a-furnace surrounding the bank of tubes, 9. superheater in one portion of the furnace, vapor generating tubes in another portion of the furnace, separate burners for firing each of said furnace portions, and partition means forming a passage around the tube bank and separating said bank from the furnace, the fur-- nace having a gas outlet opening in communication with the 'saidpassageand positioned to re-' ceive gases of combustion from said one furnace portion after the gases have passed in heat exchange relationship with the superheater and to receive the gases from said other furnace portionafter the gases have passed in heat exchange relationship with the vapor generating tubes, the said passage having a gas outlet through which gases flow from the said passage, the said passage furnace gas outlet opening and the gas outlet beingso disposed in relationship to each other and the tube bank that gases of combustion from the furnace flow into said passage through said gas outlet opening and flow in heat exchange relationship with the tube bank in flowing through said passage from said outlet opening to said outlet. I

11. A vapor generator comprising a setting, an upper vapor and liquid container, a lower liquid container below the upper container, a bank of vapor generating tubes extending between the containers, downcomer means disposed within the bank of tubes, a cylindrically shaped furnace surrounding the bank of tubes, a superheater in one portion of the furnace, vapor generating tubes in another portion ofthe furnace, said furnace portions being in communication with each other, separate burners for firing each of said furnace portions, and partition means forming a passage around the tube bank and separating said bank from the furnace, the furnace having a gas outlet opening in communication with the said passage and positioned to receive gases of combustion from both furnace portions after the gases from said one portionhave passed in heat exchangereiationshi with the superheater and after the gases from both of said furnace portions have passed in heat exchange relationship with the vapor generating tubes, the said p ssage having a/gas outlet through which gases flow from the 'passage, the furnace gas outlet opening .and the said passage gas outlet being so disposed burners spaced from each other circumferentially of the furnace, a substantially vertically extending vapor and liquid drum disposed centrally of the furnace, said drum having an upper vapor and liquid chamber, a lower liquid chamber and an elongated connecting chamber extending substantiaily vertically between said chambers, the connecting chamber being of lesser diameter than the ppper and lower chambers, a bank of vapor generating tubes adjacent the connecting chamber and connecting said upper and lower chambers, partition means forming a passage around the tube bank and separating the bank from the furnace, the furnace having a gas outlet opening in communication therewith and with the passage and through which gases of combustion produced by said burners fiou ito said passage, the passage having a gas outlet hrough which gases flow therefrom and ,from the setting, the outlet and the outlet opening being so disposed in relationship to each other that ases of combustion from the furnace flow in heat exchange relationship with the tube bank in flowing through said passage from said furnace gas outlet opening to the passage gas outlet, and a superheater disposed in heat exchange relationship with the gases flowing from at least one but not all of the burners to the gas outlet opening.

13. A vapor generator comprising a setting, an

upper vapor and liquid'container, a lower liquid container below the upper container, a bank of vapor generating tubes extending between the containers, downcomer means disposed within the bank of tubes, a furnace in the setting surrounding the bank of tubes, rows of spaced tubes furnace chamber, burner means for firing thesuperheater furnace chamber, and partition means forming 'a passage around the tube bank and separating the bank from the furnace, the

furnace having agas outlet opening in communi-- cation with the vapor generatingfurnace chamber and the passage and through which outlet gases of-combustion from both of said burner means flow into said passage, the passage having a gas outlet through which gases flow therefrom and from the setting, the outlet and the outlet opening being so disposed in relationship to each other that gases of combustion from the furnace flow in heat exchange relationship with the tube bank in flowing through said furnace gas passage from said outlet opening to the passage gas outlet opening.

14, A vapor generator comprising a setting an upperwapor and liquid container, a lower liquid 1, container below the upper container, a bank .of

the bank of tubes, a fumacein the setting sur' vapor generating tubes extending between the containers, downcomer means disposed within of combustion from both of. said burner means flow into said passage, the passage having a gas outlet through which gases flow therefrom and from the setting, the outlet and the outlet opening being so disposed in relationship to each other that gases of combustion from the furnace flow in heat exchange relationship with the tube bank in flowing through said passage from said furnace gas outlet opening to the passage gas outlet, and a superheater in said superheater furnace chamber having a portion thereof in convection heat exchange relationship and another portion in radiant heat exchange relationship with gases of combustion from the burner means for firing said superheater furnace chamber.

7. A vapor generator comprising a setting, a substantially annular furnace in the setting, a substantially vertically extending vapor and liquid drum disposed centrally of the furnace, said drum having an upper vapor and liquid chamber, a lower liquid chamber and an elongated connecting chamber extending along the vertical axis of the drum, the connecting chamber being of lesser diameter than the upper and lower chambers, a bank of vapor generating tubes adjacent the connecting chamber and connecting said upper and lower chambers, the width of the tube bank at the point of connection'with said chambers being less than the diameter of the chambers, heat insulating means separating the connecting chamber from the tube bank, rows of spaced tubes extending transversely of the furnace and dividing it into a vapor generating furnace chamber and a superheater furnace chamber, burner means for firing the vapor generating furnace chamber, burner means for firing the superheater furnace chamber, partition means forming a passage around thetube bank and'separating the bank from the furnace, the furnace having a gas outlet opening through said partition in the vapor generating furnace chamher through which gases of combustion from both of said burner means flow into said passage, the passage having a gas outlet through which gas'es flow therefrom and from the setting, the outlet and the outlet opening being so disposed in relationship to each other that gases of combustion from the furnace flow in heat exchange relationship with the tube bank in flowingthrough said passage from said furnace gas outlet opening to the passage gas outlet, '2, substantially vertically extending superheater inlet header outside of and adjacent to the superheater furnace chamber, means connecting said inlet header to the upper vapor and liquid chamber of the drum, a substantially vertically extending superheater outlet header outside of and adjacent to the superheater furnace chamber, said inlet header and said outlet header being spaced from one another circumferentially of the superheater furnace chamber', and a plurality of substantially horizontally extending superheater tubes connecting said headers, the tubes having end portions that extend from the headers transversely of the superheater chamber thence toward the headers to the inner peripheral wall of the furnace and a portion intermediate the end portions extending along said peripheral wall of the furnace. I

8. A vapor generator comprising a setting, 'a substantially annular furnace in the setting, a substantially vertically extending vapor and liquid drum disposed centrally of the furnace, said drum having an upper vapor and liquid chamber, a lower liquid chamber and an elongated connecting chamber extending along the vertical axis of the drum, the connecting chamber being of lesser diameter than the upper and lower chambers, a bank of vapor generating tubes adjacent the connecting chamber and connecting said upper and lower chambers, the width of the tube bank at the point of connection with said chambers being less than the diameter of the chambers, heat insulating means separating the connecting chamber from the tube bank, rows of spaced tubes extending transversely-of the furnace and dividing it into a vapor generating furnace chamber and a superheater furnace chamber, burner means for firing the vapor generating furnace chamber, burner means for firing the superheater furnace chamber, partition means forming a passage around the tube bank and separating the bank from the fuijnace, the furnace having a furnace gas outlet opening in communication with the vapor generating furnace chamber and the passage and through which gases of combustion from both of-said burner means flow into said passage, the passage having a passage gas outlet through which gases flow therefrom and from the setting, the outlet and the outlet opening being so disposed in relationship to each other that gases of: combustion from the furnace flow in heat exchange relationship with the tube bank in flowing'through said 4 passage from said outlet opening to the outlet, an annular upper header adjacent the top of the peripheral wall of the furnace, tubular means connecting the annular upper header and the upper vapor and liquid chamber, an annular lower header adjacent the bottom of the peripheral wall of the furnace, tubular members connecting the annular lower header and the lower liquid chamber of the drum, tubes extending between said upper and lower headers along the peripheral wall of the vapor generating surface. other tubes connected at their opposite ends to said upper and lower annular headers, said other tubes having end portions which extend respectively transversely and radially of the roof and floor of the annular furnace and an intermediate portion extending substantially vertically along said partition means, and a superheater disposed in the superheater furnace chamber.

9. A vapor generator comprising a setting, a furnace in the setting, means for firing the furnace, a substantially vertically extending vapor and liquid drum in the setting having an upper vapor and liquid chamber, a lower liquid chamber chambers being less than the diameter of the chambers, heat insulating means separating the connecting chamber from the tube bank, partiauspice I rounding the bank of tubes, a superheater in one portion of the furnace, said superheater having a part thereof in radiant heat exchange relationship and another part in convection heat exchange relationship with gases of combustion in said one portion, vapor generating tubes in another portion of the furnace, separate burners for firing each of said furnace portions, and partition means forming a passage around thetube bank and separating said bank from the furnace, the furnace having a gas outlet opening in communication with the passage and positioned to receive gases of combustion from said one furnace portion after the gases have passed in heat ex change relationship with the superheater and to receive the gases from said other furnace portion after the gases have passed inheat exchange relationship with the vapor generating tubes, the passage having a gas outlet through which gases fiow from the passage, the furnace outlet opening and the gas outlet being so disposed in relationship to each other that gases of combustion from the furnace flow in heat exchange relationship with the tube bank in flowing through said passage from said outlet opening to the outlet.

15. A vapor generator comprising a setting, a substantially annular furnace in the setting having a vapor generating chamber'and asuperheater chamber therein, said chambers being in communication with one another, an upper vapor and liquid container, a lowerlfquid container below and in substantial vertical alignment with the upper container, a bank of vapor generating tubes extending between the containers. downcomer means disposed within the bankof tubes, burner means for firing the vapor generating furnace, burner means for firing the superheater furnace chamber, partition means forming a passage around the tube bank and separating the bank from the furnace, the furnace having a gas outlet opening in communication with the vapor generating furnace chamber and the passage and through which gases of combustion from both of said burner means flow into said passage, the

passage having a gas outlet through which gases flow therefrom and from the setting, the outlet and the outlet opening being so disposed in relationship to each other that gases of combustion from the furnace flow in heat exchange relationship with the tube bank in flowing through said passage from said furnace gas outlet opening to the passage gas outlet, and a superheater in said superheater furnace chamber comprising tubular members having a portion thereof extending cr'rcumfere'ntialiy along the wall of said chamber and in radiant heat exchange relationship with gases'of combustion and'another portion extending into the path of and in convection heat exchange relationship with gases flowing from the superheater chamber to the vapor generating furnace.

16. A vapor generator comprising a setting, a substantially annular furnace in the setting having a vapor generating chamber and a superheater chamber therein, said chambers being in communication with one another. an upper vapor and liquid container, a lower liquid container below and in substantial vertical alignment with the upper container, a bank of vapor generating tubes extending between the containers, downheater furnace chamber, partition means forming a passage around the'tubebank and separating the bank from'the furnace, the furnace having a gas outlet opening through "said partition in the vapor generating furnace chamber through which gases of combustion from both of said burner means flow into said passage, the passage having a gas outlet through which gases flow therefrom-and from the setting, the outlet and the outlet opening being so disposed in relalet header being spaced from one another circumferentially of thesuperheaterfurnace chamber,

and a plurality of substantially horizontally extending superheater tubes connecting said headers, the tubes having end portions thatextend from the headers transversely of the superheater chamber thence toward the headers to-the inner peripheral wall of the furnace and a portion intermediate the end portions extending along said pe rh ral wall of the furnace.

17. A vapor generator comprising a setting, a substantially annular furnace in the setting having a vapor generating chamber and a superheater chamber therein, said chambers being in communication with one another, an upper va por and liquid container, a lower liquid contalner below and in substantial vertical alignment with the upper container, a bank of vapor generating tubes extending between the containers, downcomer means disposed within the bank of tubes, burner means for firing the vapor generating furnace chamber, burner means for firing the superheater furnace chamber, partition means forming a passage around the tube bank and separating the bank from the furnace, the furnace having a gas outlet opening through said partition in the vapor generating furnace chamber through which gases of combustion from both of said burner means flow into said .passage, the passage having a gas outlet through which gases flow therefrom and from the setting, the outlet and the outlet opening being so disposed in relationship to each other that gases of combustion from the furnace flow in heat exchange relationship with the tube bank in fiowing through said passage from said furnace gas outlet opening to the passage gas outlet, an annular upper header adjacent the top of the peripheral wall of the furnace, tubular means connecting the annular upper header and the upper vapor and liquid chamber, an annular lower header adjacent the bottom of the peripheral wall of the furnace, tubular members connecting the annular lower header and the lower liquid chamber of the drum, tubes extending between said upper and lower headers along the peripheral wall of the vapor generating surface, other tubes connected at their opposite ends to said upper and lower annular headers, said other tubes having end portions which extend respectively transversely and radially of the roof and floor of the annular furnace and an intermediate portion extending substantially vertically along said partition means, and a superheater disposed in the superheater furnace chamber.

asiaesa 18. A vapor generator comprising a setting having a substantially annular furnace chamber therein, an upper vapor and liquid container, a lower liquid container below and in substantial vertical alignment with the upper container, a bank of vapor generating tubes extending between the containers, downcomer means disposed within the bank of tubes, burners spaced from each, other circumferentially of the furnace, partition means forming a passage around the tube bank and separating the bank from the furnace, the furnace having a gas outlet opening through said partition so positioned that gases of combustion from both of said burner means flow into said passage, the passage having a gas outlet through which gases flow therefrom and from the setting, the outlet and the outlet opening being so disposed in relationship to each other that gases of combustion from the furnace flow in heat exchange relationship with the tube bank in flowing through said passage from said furnace gas outlet opening to the passage gas outlet, an annular upper header adjacent the top of the peripheral wall of the furnace, tubular means connecting the annular upper header and the upper vapor and liquid chamber, an annular lower header adjacent the bottom of the peripheral wall of the furnace, tubular members connecting the annular lower header and the lower liquid chamber of the drum, tubes extending between said upperand lower headers along the peripheral wall of the vapor generating surface, and other tubes connected attheir opposite ends to said upper and lower annular headers, said other tubes having end portions which extend respectively transversely and radially of the roof and floor of the annular furnace and an intermediate portion extending substantially vertically along said partition means.

19. A vapor generator comprising a setting, a furnace in the setting, means for firing the furnance, an upper vapor and liquid container, 2. lower liquid container below and in substantial vertical alignment with the upper container, a bank of vapor generating tubes extending between the containers, downcomer means disposed within the bank of tubes, an annular of!- take pipe adjacent the upper end of said upper container, means communicating with said pipe and the upper chamber through which vapor passes from said upper container into the off-' take pipe, partition means forming a passage around the tube bank and separating said bank from the furnace, the passage having a gas inlet opening adjacent one end thereof in communication therewith and with the furnace and a gas outlet opening through which gases flow from the passage, the inlet and outlet openings necting chamber and 1 being so disposed in relationship to each other that gases of combustion from the furnace flow in heat exchange relationship with the tube bank in flowing-through said passage from the'inlet to the outlet thereof, and centrifugal vapor and liquid separating means in the upper vapor and liquid chamber comprising a cylindrical member having an opening in the upper part in communication with said chamber and the interior of the cylindrical member, means forming curved passages in said opening for imparting a whirling movement to the vapor and liquid, the cylindrical member having a liquid outlet at the bottom thereof in communication with said cona vapor outlet in communication with the means communicating with the annular oiftake pi 20. A vapor generator comprising a setting, an upper vapor and liquid container, a lower liquid container below the upper container, a bank of vapor generating tubes extending between the containers, downcomer means disposed within the bank of tubes, a furnace surrounding the bank of tubes, means for supplying air under pressure to the furnace, a superheater in one portion of the furnace, vapor generating tubes in another portion of the furnace, separate burners for firing each of said furnace portions, and partition means forming a passage around the tube bank and separating said bank from the furnace, the furnace having a gas outlet opening in communication with the passage and position to receive gases of combustion from said one furnace portion after the gases have passed in heat exchange relationship with the superheater and to receive the gases from said other furnace portion after the gases have passed in heat exchange relationship with the vapor generating tubes, the

- passage having a gas outlet through which gases said passage from said flow from the passage, the furnace outlet opening and the gas outlet being so disposed in relationship to each other that gases of combustion from the furnace flow in heat exchange relationship with the tube bank in flowing through outlet opening to the out- MARTIN FRISCH.

REFERENCES CITED UNITED STATES PATENTS let.

Number Name Date 760,373 Beam May 17, 1904 978,009 Engel Dec. 6, 1910 1,935,659 Noack Nov. 21, 1933 2,044,270 Wood June 16, 1936 

